Binary codable, cam operated, pivoted contact switch assembly

ABSTRACT

This invention relates to a switch having four parts including the housing. More particularly the invention relates to a frame which has 16 positions which can be binary coded. The 16 positions consist of four single pole-double throw contacts all of which are made by stamping and forming a single sheet of metal. The movable contacts are switched from one fixed contact to another by lobes on a rotatable camshaft.

.[lli 3,792,206

[451 'Feb. 12,1974

United States Patent [191 Purdy BINARY CODABLE, CAM OPERATED,

PIVOTED CONTACT SWITCH ASSEMBLY Primary ExaminerJ. R. Scott [75] inventor: Harold Lawrence Purdy,

Hummelstown, Pa.

[73] A'ssignee:

AMP Incorporated, Harrisburg, Pa.

Nov. 13, 1972 Appl. No.: 306,113

[22] Filed:

ABSTRACT This invention relates to a switch having four parts including the housing. More particularly the invention relates to a frame which has 16 positions which can be binary coded. The 16 positions consist of four single pole-double throw contacts all of which are made by stamping and forming a single sheet of metal. The

movable contacts are switched from one fixed contact to another by lobes on a rotatable camshaft.

References Cited UNITED'STATES PATENTS 3,359,392 l2/l967 Heath 200/6 BA UX 4 Claims, 7 Drawing Figures PATENIED FEB I 2W4 smn 2 or 4 PATENIEDFEBI emu SHtEI 0? 4 BACKGROUND OF THE INVENTION -ular circuit board which is only one among many allelectrically connected boards, an addressing signal must be sent preceding the message. A selective switch which is mounted on each board is programmed to open the door to its board only when the addressing signal matches a particular code therein. The code will consist of a number of circuits which are opened or.

closed in a pre-determined combination. An analogy to this electronic switch is the manually operated combination lock.

Selective switches currently available are made from a large number of parts. For example, somecontact arms are separately fashioned with a highly conductive contact point being riveted or soldered thereonto. Thus, in a switch having four poles, and with double throw (four movable contacts and eight fixed contacts) there could be a minimum of 28 separate pieces in the contact assembly alone. Added to these 28 pieces, there are detent springs, detent plates and so forth. Obviously, this type of switch is costly to make and further the manufacturing process not lend itself readily to automation.

Another problem which workers in this field are faced with is the spacing between printed circuit boards in installations such as computers, telephone exchanges, airplanes and the like As space is generally at a premium in such installations, the circuit boards are stacked as close together as possible. The pluggable components such as the 'selective switches must have as low a profile as possible. The miniaturization of a large number of discrete parts obviously increases manufacturing costs as well as decreases operating life and reliability. l

Accordingly, it is an object of the present invention to provide a complex 16 position binary codable selective switch having four discrete parts including the housing and which can be mass-produced using high speed automation.

Another object of thepresent invention is to produce aswitch adapted to control electric circuits on a selective basis. 1 1

Other objects and features of the invention will become apparent from the following description of the preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view of a completely assembled binary codable selective switch;

FIG. 2 is an exploded view of a preferred embodiment of the switch in FIG. 1 less the cover;

FIG. 3 is the contact frame of FIG. 2 after stamping operations;

FIG. 4 is the contact frame of FIG. 3 after forming operations; FIGS. 5 and 6 are cross-sectional views taken along lines 55 and 66 respectively of FIG. I; and

FIG. 7 is another preferred embodiment of the present invention.

DESCRIPTION- OF THE PREFERRED EMBODIMENT FIG. 1 illustrates a completely assembled binary codable dual in-line package switch 10 ready for use in a printed circuit board (not shown) or the like. The components of switch 10 include the upper cover member 12 of housing 13. Depending from the housing are pins or connecting posts 14 which are adapted to be received in female receptacles, sockets, or holes in a printed circuit board (not shown). The end wall 16 of cover member 12 has an opening 18 in which is positioned the slotted end 20 of camshaft 38 (FIG. 2). Encircling opening 18 are position indicators 22.

FIG. 2 is an exploded perspective view of the components within switch 10. The lower half of housing 13 is base member 24 having sidewalls 26 on which are contained on its outer surface, vertical grooves 28. End walls 30 have elongated, U-shaped slots 32 opening upwardly. Intermediate to end walls 30 isa dividing wall 34 which sections the interior of base member 24 into two compartments 35. As with walls'30, dividing wall 34 also has a U-shaped upwardly opening slot 32.

Immediately above base member 24 is the aforementioned camshaft 38. The camshaft has three annular bearing surfaces 39, one on either end (only the right sided one can be seen) and a third one in the middle which separates camshaft 38 into two halves. Both halves contain two distinct, side by side cams 44 positioned between two detent surfaces 46. The positioning of the flanks 47 and lobes 48 on earns 44 have been pre-determined to yieldspecific results as will be discussed below. The detent surfaces 46 contain a plurality of hills 49 and valleys 50. In the assembled switch camshaft 38 is positioned within the base member 24 with annular bearing surfaces 39 rotatably positioned in slots 32 and each half of the camshaft in one of the two comparments 35.

' Positioned above camshaft 38 are a plurality of contact members 56. The members each have a shank or intermediate portion 58, the aforementioned posts 14 at the outer ends, and on the other end inner portions Which have been bent normal to the intermediate portion 58. As these contact members form an important part of the instant invention, they will be considered in detail below. Suffice it to say that there are four detent springs 62 andfour movable contact arms 64 each of which are engageable with two fixed contacts 66-68.

In the assembly of switch 10, the contact members 56 fit down over the camshaft 38 positioned in base member 24 with the inner portions 60 extending across the openings of compartments 35 with each of the movable contact arms 64 in registration with one of the four cams 44. Each of the'four detent springs 62 are loaded against one of the four detent surfaces 46 so that a firm intentional effort is required to rotate camshaft 38 and so that the camshaft is .protected against unintentional movement induced by vibrations. To this end, the debe used, phosphor bronze has been found to work quite satisfactorily.

In FIG. 3 a frame 70 has been stamped from a strip roll of metal (not shown). On either end are connecting straps 72 which lead to and from other like frames (not shoWn). Running transverse to and integral with straps 72 are two end strips 74, each-F which contain a positioning hole 76 located on the frames longitudinal axis. Between the end strips and parallel thereto are the two rows of eight contact members 56 each. The posts 14 extend outwardly and the contact portions 60 project inwardly with respect to the frames longitudinal axis.

Web portions 78 connect members 56 with end strips 74. These web portions are located adjacent to posts 14. Although this location for the web portlons is preferred because it adds stability to the contact members 56 both during the forming operation and assembly of switch 10, it has been. found that the removal of the web portions subsequent to assembly is facilitated if such portions are located at or near the free ends of posts 14.

FIG. 4 shows frame 70 after the forming operation.

The midsections of end strips 74, hereinafter designated generally at 80, and inner portions 60 have been bent to form the bight on the U-shaped configuration while the ends of end strips 74, posts 14, intermediate portions 58 and web portions 78 form the legs.

Each contact member 56 is separately identified by a small letter beginning with a, attached to the reference numeral 56 for the purpose of describing the structure of the inner portions 60.

The contact portion of member 56a is biased or loaded downwardly relative to midsection 80 and further a section designated at 82 and adjacent the free end of the inner portion, has been dimpled to form detent spring 62 (FIG. 2).

The contact portions of contact member 56b, contains a laterally extending tab 84 which has been bent so that its contact area 85 is in a higher horizontal plane than for example the midsection 80 of end strip 74. Tab 82 so formed is the fixed contact 68 (FIG. 2).

The inner portion 60 I of contact member 560 (adjacent to 56a) has been swaged as seen at 86. The swaging has extruded the contact portion further toward and overlaps, its opposing contact member (56d) and extends beneath lateral tab 84; i.e. fixed contacts 66 and 68. Further, the swaging has increased the flexibility of the innerportion 60 and has hardened the material allowing higher stress levels. The contact portions of 56c have also been dimpled. between the free end and the swaged area to create a convex surface 88 which is dimensioned to rest conformably in a flank 47 on cam 44 (see FIG. 5). The inner portion 60 on contact member 560 formed as described above constitutes movable contact arm 64 (FIG. 2). The inner portion 60 of contact member 56d, positioned adjacent member 56b and oppose member 56c is generally rectangular platform 90 which constitutes the fixed contact 66 (FIG. 2). As the platform on contact member 56d has been obscured in FIG. 2 by movable contact arm 64, reference is made to contact member 56f which clearly show the platform and as will be seen is identical thereto.

Contact members 56a, b, c,' and d form on set consisting of a detent spring 62, movable contact arm 64 and fixed contacts 66- 68. This set has a mirror image in all respects in members 56e, f, g, and h. These two sets 4 form a first group having double pole-double throw characteristics. A second group but orientated degrees therefrom, consists of contact members 561', j, k, l, m, n, 0, and p. The two groups together, along with the particular cam "44 configurations, operate in 8-4-2-1 binary sequence. As is apparent, the cam 44 configuration and contacts can be varied to produce any sequence as desired. one

FIG. 5 clearly shows the relationship between the several components in switch 10. Camshaft 38 is seen rotatably positioned in base member 24 of housing 13 with annular bearing surfaces 36 seen in phantom positioned in openings 32. The figure also clearly shows the swaged area 86 on movable contact arm 64 as well as the positioning of its free end in between the two, vertically spaced-apart, fixed contact 66-68. Contact arm 64, biased against fixed contact 66, is moved into engagement with fixed contact 68 by rotating camshaft 38 to where a lobe 48 elevates the arm. 7

FIG. 5 also shows the general construction of cover member 12 and its relation to contact members 56 and base member 24. As is well understood in the art, the housing members are bonded together to make an environmentally sealed package.

FIG. 6 illustrates the relation of detent spring 62 to detent surface 46. The view shows the interaction between dimple 82 and the hills 49 and valleys 50 on surface 46. The angles thereon are steep to require some force to rotate camshaft 38 and also to provide a snap action as detent springs 62 cam over a hill into a valley.

FIG. 6 also includes an end view of fixed contact 68 showing the vertical offset thereof.

FIG. 7 illustrates the adaption of the switch disclosed herein to a single pole (one movable contact arm 62) and a single throw (fixed contact 66). It is clear that fixed contact 68 could be used in lieu of contact 66. Camshaft 38 incorporates a single cam 44 having a single lobe 48. Base member 24 has but a single and shorter compartment 35 and of course cover member 12 would also be proportionately smaller.

It is apparent that cam 48 in FIG. 7 could have a single flank 47 instead of a single lobe 48.

With the exceptionof contact members 56 the other three components of switch 10; i.e., cover and base members 12-24 and camshaft 38, are made of plastic or other insulating material.

In summary the present invention discloses a switch consisting of a limited number of easily available components with the contact members being made from a single strip of material by stamping and forming without adding another single discrete element. However, as is well known in the industry, the contact members may be plated with gold, tin or the like to enhance the metals electrical characteristics but this 'is a matter of choice rather than need.

The present invention is ideally suited for use as an address to a printed circuit board such that access to the board is gained only by a select signal. It is apparent to one skilled in the art that a board having thereon the switches herein disclosed can be given a new address at any time without removing the switches from the board and with the only required tool being a screwdriver.

it is further apparent that the switch disclosed herein, having a total of four parts, is readily adaptable to manufacturing via automation.

The present invention is not limited to a single pole, single throw or a dual double pole, double throW embodiments. It will be clear to those skilled in the art that any number of combinations can be made.

The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, as some modifications Will be obvious to those skilled in the art.

I claim: 1. A selective switch assembly comprising: a. an insulating housing having an opened compartment therein; b. a first contact member stamped and formed from a coplanar sheet of conductive material and comprising i. an intermediate portion extending along a sidewall of 'said housing, ii. a post at one end of and integral with said intermediate portion and depending 'from said housiii. an inner portion integral with said intermediate portion and extending into the space above said opened compartment of said housing, said inner portion forming one fixed contact;

c. a second contact member stamped and formed from the same coplanar sheet of conductive material as said first contact member and comprising, i. an intermediate portion extending along another sidewall of said housing,

ii. a post integral with said intermediate portion and depending from said housing,

iii. an inner portion integral with said intermediate portion and extending across said opened compartment of said housing toward said fixed contact, said inner portion being swaged adjacent said intermediate portion to extrude the free end thereof into an' overlapping relation to said fixed contact, said inner portion forming a movable contact arm;

d. cam means in said compartment for moving said movable contact arm into and out of engagement with said fixed contac; and

e. insulating cover means for covering said opened comartment.

2. The selective switch assembly of claim 1 wherein the assembly includes:

a. a stamped and formed third contact member comprising an intermediate portion extending along a sidewall of said housing in parallel relation to said intermeditate portion of said first contact member, a post integral with said intermediate portion and depending from said housing, and an inner portion integral with and normal to said intermediate portion and extending into the space above said opened compartment of said housing, said inner portion having a tab thereon forming a second 'fixed contact, said second fixed contact extending laterally over and spaced above said one fixed contact, with said movable contact arm being positioned thereinbetween; and

b. said cam means includes means thereon for moving said movable contact arm from said one fixed contact to said second fixed contact.

3. The selective switch assembly of claim 1 wherein said assembly includes:

a. a detent surface on said cam means; and

b. a stamped and formed fourth contact member 4. A switch assembly comprising a. a base member having sidewalls having spaced vertical grooves, endwalls having U-shaped slots therein, a mid-wall intermediate said endwalls and parallel thereto, said mid-wall having a U-s'haped slot therein, two open compartments defined by said sidewalls, endwalls and mid-wall;

b. a camshaft rotatably positioned in said base member, said camshaft having, end bearing surfaces received in said endwall U-shaped slots, a middle bearing surface intermediate said end bearing surfaces and received in said mid-wall U-shaped slot, four detent surfaces, each being positioned immediately adjacent an end bearing surface and two being one on either side of said middle bearing surface, four cams having lobes thereon, two of said cams positioned between one of said end bearing surfaces and said middle bearing surface and another two cams positioned between another of said end bearing surfaces and said middle bearing;

. 16 contact members stamped and formed from a single coplanar sheet of conductive material, said contact members being formed into two groups in tandem fashion with each group having two sets and with each set comprising four contact members, each contact member having an intermediate portion received in one of said vertical grooves on said sidewals, a post portion integral with and extending from said intermediate portion and depending below said base member, and an inner portion integral with another end of said intermediate portion and extending over said opened compartment, a first of said inner portions including a short projection thereon forming a first fixed contact, a second of said inner portions positioned adjacent said first inner portion and having a tab thereon forming a second fixed .contact, said second fixed contact extending laterally across and spaced above said first fixed contact, a third inner portion positioned opposite said first fixed contact and having a movable arm with a free end positioned between said first and second fixed contacts, said arm forming a movable contact arm, and engageable by one of said cams so that as said camshaft rotates, said cam moves said movable contact arm from one fixed contact to another, and a fourth inner portion positioned adjacent said movable contact arm and opposite said second fixed contact, said inner portion having an elongated arm with a convex surface thereon in biasing engagement with one of said detent surfaces on said camshaft, said elongated arm forming a detent spring; and

d. a housing cover adapted to fit down over said contact members and said base member. 

1. A selective switch assembly comprising: a. an insulating housing having an opened compartment therein; b. a first contact member stamped and formed from a coplanar sheet of conductive material and comprising i. an intermediate portion extending along a sidewall of said housing, ii. a post at one end of and integral with said intermediate portion and depending from said housing, iii. an inner portion integral with said intermediate portion and extending into the space above said opened compartment of said housing, said inner portion forming one fixed contact; c. 2 second contact member stamped and formed from the same coplanar sheet of conductive material as said first contact member and comprising, i. an intermediate portion extending along another sidewall of said housing, ii. a post integral with said intermediate portion and depending from said housing, iii. an inner portion integral with said intermediate portion and extending across said opened compartment of said housing toward said fixed contact, said inner portion being swaged adjacent said intermediate portion to extrude the free end thereof into an overlapping relation to said fixed contact, said inner portion forming a movable contact arm; d. cam means in said compartment for moving said movable contact arm into and out of engagement with said fixed contac; and e. insulatIng cover means for covering said opened comartment.
 2. The selective switch assembly of claim 1 wherein the assembly includes: a. a stamped and formed third contact member comprising an intermediate portion extending along a sidewall of said housing in parallel relation to said intermeditate portion of said first contact member, a post integral with said intermediate portion and depending from said housing, and an inner portion integral with and normal to said intermediate portion and extending into the space above said opened compartment of said housing, said inner portion having a tab thereon forming a second fixed contact, said second fixed contact extending laterally over and spaced above said one fixed contact, with said movable contact arm being positioned thereinbetween; and b. said cam means includes means thereon for moving said movable contact arm from said one fixed contact to said second fixed contact.
 3. The selective switch assembly of claim 1 wherein said assembly includes: a. a detent surface on said cam means; and b. a stamped and formed fourth contact member comprising an intermediate portion extending along a sidewall of said housing in parallel relation to said intermediate portion of said second contact member, a post integral with said intermedate portion and depending from said housing, and an inner portion integral with said intermediate portion and extending into said opened compartment into biasing engagement with said detent surface on said cam means, said inner position on said fourth contact member forming a detent spring.
 4. A switch assembly comprising a. a base member having sidewalls having spaced vertical grooves, endwalls having U-shaped slots therein, a mid-wall intermediate said endwalls and parallel thereto, said mid-wall having a U-shaped slot therein, two open compartments defined by said sidewalls, endwalls and mid-wall; b. a camshaft rotatably positioned in said base member, said camshaft having, end bearing surfaces received in said endwall U-shaped slots, a middle bearing surface intermediate said end bearing surfaces and received in said mid-wall U-shaped slot, four detent surfaces, each being positioned immediately adjacent an end bearing surface and two being one on either side of said middle bearing surface, four cams having lobes thereon, two of said cams positioned between one of said end bearing surfaces and said middle bearing surface and another two cams positioned between another of said end bearing surfaces and said middle bearing; c. 16 contact members stamped and formed from a single coplanar sheet of conductive material, said contact members being formed into two groups in tandem fashion with each group having two sets and with each set comprising four contact members, each contact member having an intermediate portion received in one of said vertical grooves on said sidewal s, a post portion integral with and extending from said intermediate portion and depending below said base member, and an inner portion integral with another end of said intermediate portion and extending over said opened compartment, a first of said inner portions including a short projection thereon forming a first fixed contact, a second of said inner portions positioned adjacent said first inner portion and having a tab thereon forming a second fixed contact, said second fixed contact extending laterally across and spaced above said first fixed contact, a third inner portion positioned opposite said first fixed contact and having a movable arm with a free end positioned between said first and second fixed contacts, said arm forming a movable contact arm, and engageable by one of said cams so that as said camshaft rotates, said cam moves said movable contact arm from one fixed contact to another, and a fourth inner portion positioned adjacent said movable contact arm and opposite said second fixed contact, said inner portion having an elongated arm with a convex surface thereon iN biasing engagement with one of said detent surfaces on said camshaft, said elongated arm forming a detent spring; and d. a housing cover adapted to fit down over said contact members and said base member. 